Process for the recovery of gum constituents from asclepiadaceae and product



LOUGOVOY EI'AL PROCESS FOR THE RECOVERY OF GUM CONSTITUENTS FROM ASCLEPIADACEAE AND PRODUCT Filed Jan. 13, 1945 2 Sheets-Sheet- 1 FZANTS' EIPINDER szuvs REEUYERY VALULI M PAN INVENTOR.

B. N. LOUGOVOY El AL 2,397,611- ;PROCESS FOR THE RECOVERY OF GUM CONSTITUENTS April 2, 1946.

FROM ASCLEPIADACEAE AND PRODUCT Filed Jan. 15,-'1943 2 Sheets-Sheet 2 Tu EENZDL WA TEE. SEPARATUR RECOVERED BENZUL QmuhsExm INVENTOR.

l-HUT WATERJAL'K ET' COLD WATER JACKET Patented Apr. 2, 1946 AND PRODUCT CONSTITUENTS J FROM .ASCLEBIADAGEAE Boris N. Lougovoy, Jackson" Heights, N. Y., and

Carl E. Hartwig, Teaneck,'NJ.

Application January 13, 1943,:Serial No. -472,29o l 6 Claims.

The object of the present invention is to provide a process. for the recovery of valuable gum constituents of the plants belonging to the Asclepiadaceae 'family, commonly known as the 'milkweed, and in one phase of the invention, to

obtain a product having physical characteristics similar to chiclein that it. will solidify into a block which at room temperatures will snap-break and not be rubbery and flexible.

"The present process is based upona treatment of the dried and ground plantby solvent extraction and other steps of such character as to overcome very diflicult problems due to the character of the soluble constituents of the dried plant.

half feet, with corresponding increase in stem' diameter and leaf size.

The lactiferous system of the plants consists of branched tubes or canals which extend through the stems, petioles and leaves.

In" treating. the dried: and ground plant material by standard: solvent extraction methods and even-with thorough liberation of solvent from the recovery, the product is a dark soft viscid and sticky mass, with an objectionable pungent haylike odor, the material being entirely unsuited'for the desired purpose.

Upon our development of a method for ubstantially removing the coloration constituents, these constituents being primarily chlorophyl, the product remained soft and tacky, possessed poor elasticity and retained its pungent odor. It was then discovered that the odor was due tothe presence of a vegetable oil in the product, and that the removal thereof could be efiected and that such removal tookaway a great part of the tackiness, increased the hardness, notwithstanding the fact that the proportion of oil in the plant is very small indeed. It was also found possible to so treat the resulting product that objectionable waxes were removed, this removal being selective, i. e., in such manner that harder and desirable waxes were not affected. Finally, a process was developed, as now to be described, which was certain, effective, and entirely commercial, resulting in a product excellent as a major component of a highzgrade chewing gum base.

-I-n-tdescribing the process, reference will be made ;-to;.thev accompanying drawings which diagram.

maticallywillustrate three formsaof suitable:-.apparatus; employedpandfin which Figure: lrconstitutesaazfiow; sheet :in apparatus employingzanadsorber; I I

j Figure "2 diagrammatically. .iilustratesea duplex apparatus.

' Figure '3. diagrammatically .illustratesaa; simplifled apparatus.

.The;:apparatusyillustrated;in:Figure .1: consists of an: extractor. I: providedxwithaa receiving. aperture. lzcxfor the plant;particleszan'dwitha solvent :inletuZ. The extractorziistormed :with 'a -baseidischarge outlet lam: .leadingtdn dehydrator; 3;: the latter discharging- 1intoxansadsdrber'l. .Ther'solution feed .from' the adsorber l'e'adsto a :filter 5 discharging into: a stillsli, .theisolvent' Vapors? from the stilLme'eting. a. condenser: hand the condensate flowing toa solventvessel Ta.

. The: solution, substantially solvent: .free, Passes toavacuunrpan- 8 fromrwhichzwater vapors and remaining traces of solvent are; removed. The vaporsxare: condensedwat' 9;: the: water: separated "at In; andtherliquid solvent zl'ed'toa solvent vessel The solvent collected fin": vessels 11a, H,. is re-zpassed. to the; extracting 've'ssellvia' conduit l 2, and the intermediate tank. 13. iThe' extractor may be:fitted withria jacketed solvent intakeline, so 2' that the temperaturersnfy; th olv nt aanb regulated :at 1 any :Idesired utemperaiture. Room ci'ent.

In determining the solvent, it was found-that the solventszindi'oated because of their efiiciency with respect to"the:materia'1 treated," such as trichlorethylene, hexane and chloroform, so depreciated .the finally'recovered gum thatii; was an inferior rproduct, b'eing isoft and viscous and not lending :itselfsto purification. -The aromatic-sob vents benzol, toluol and xyl'ol; :were found to have no. deleterious efiectxand, in the orderstate'd; to

.besatisfactory. .Als -ioecause oft-special advantagestin the. process; as 'later to-bedescribed, V. M-'P. solvent" naphtha (Standard 01100. oi'N'ew Jersey )xis preferred; i a

The" first step. in. the proceSsds-t'o grind the dried plants: "into particles which will preferably pass through a 10='mesh-"scre'en ('SAE' gauge). WhenJthusground' the cells of theplant are broken and' opened 'so' that the cell'contents may be dissolved out. 25- pounds-of the dry ground plantparticles are placed in the extractor, and thereupon 10 gallons oi"- solvent "arecirculated for five hours through the "particles a cycle being a completed in three-minutes. The solution-is then led to't'he dehydrator 3 "followingnwhich temperature of thezsolventiwili:2:genera1ly"be s'uiflthe dehydrated solution is passed to the absorber 4. The reason for dehydrating the solution is that in the preceding extraction after draining the extractor, there remains therein a proportion of solvent held by the drained plain particles. Steam, therefore, is preferably employed to drive off and thus recover such solvent, and this inevitably results in the retention of a minor moisture content within the extractor which is picked up bythe subsequent extraction-solution. The.

3 presence of even traces of moisture in the solution will interfere with the removal by adsorption of chlorophyl and also will rapidlycause'sealing of the filter subsequently used by the adsorbing material employed. The adsorber 4 is one.

means of effecting our discovery that the highly objectionable chlorophyl maybe removed from" the solution by selective adsorption. Infusorial due to the hydrophylic properties of the gum, i. e., its ability to absorb a certain amount of moisture from the steam. In the operation of the steam still or vacuum pan, the pressure may be held at from 5 to lOpounds of steam until the solvent is completely removed, whereupon the steam pressure may be slowly increased, with care to prevent foaming, until at a, pressure of 35 pounds the steam may continue through the mass for one hour, the time of total steam treatment thus may be about one and one-half hours.

The oil and water vapor passes upward through conduit 8:: to condenser 9, accompanied by solvent vapors, and separation is effected by the charge pipe Ila: to the solvent vessel ll,

water being decanted.

earth (such as fullers earth) or its equivalent, is 1 efiective,.inasmuch as neither the desired gum constituents nor the waxes are affected.v The usual coloration adsorbing vmaterials suchas charcoal, activated carbon, aluminum oxide,

silica gel, are ineffective because of the peculiar nature of the present solution in whichithe chlorophyl is contained. I '-"The adsorption material in suitable 'quantity pounds of fullers earth to the solution drained from pounds. of ground'plant, i. e., 9 ga1lons,is

adequate! Completel adsorption is effected in j about forty-five minutes and the contents of the adsorber are constantlystirred.

We have found that the adsorption is more efiloiently effected by the addition 10f adsorption material'to the solution in successive relatively small batches. Thus'in the use of 4 pounds of adsorption material 2 pounds may be initially placedin the adsorberand the stirring continued for twenty minutes. At this point an additional pound of adsorption material is added and the [stirring continued for twelve minutes, at-which .time-thefourth pound is added and the stirring completed in thirteen minutes. I

.Chlorophyl is removed becauseof these three objectionable features: (it) Its deleterious effect as an emulsifying agent inthep of water and tends to break down thegum;

may be placed in the adsorber andabout four o-n the desired char- -acteristics-ofthe final'productin that it acts (b) It produces tackiness and softness in the v gum; and.

(c) It provides a fairly permanentlcoloration,

,particularlyinthe presence ofzwater.

If, now, the solution is filtered and the solvent distilled 011', the resulting product is pale yellow vin color, rather soft and sticky and gradually .sets up into a softfriablenon-sticky mass, and

it has a strong hay-like odor. It contains gutta,

)resins, waxy materials ofymutually difierent characteristics, a vegetable oil and fatty acids.

-At this stage it is entirely possible to employ the i product for blending in larger proportion with other crude gums, such as .Gutta Hang Kang and'Perillo Colombian,- toiprovide a major com ponent for a-gooid-chewing-gum' base.

For improvement of the recovered materialthe separator Hi, the solvent flowing through disthe It is pref rred thatin the steam distillation calcium oxide in finely powdered form be placed in the still and in proportion [10th of 1% of the calculated gumcontent, i.e.; ifthestillihasa capacity of 1000.pounds; the calciumoxide will be 1 pound. Calcium oxide has the double'function of adding a suitable inert extender, .and to neutralize any free fatty acids which maybe present, the latter being fixed as calcium soap.

After the 'gum has been steamed; itis with: drawn from thesteam still and placed-ma heat.-

ing or drying pan and with slow agitation it is heated until maximum foaming occurs- Atthispoint it is withdrawn from the pan and may be filled in molds and allowed to cool.

-A further improvement was .eifected by the selection of V. M. Pxsolvent naphtha as the solvent and the use of furfural in a step'of the process with the resultthat the Waxes were selectively acted upon with removal of the objectioi'i able'softer waxes and retention of 'theharder and. desirable waxes. 'It was found that the V.

M. P. solvent naphtha is a complete solvent for the soluble constituents of the ground plant par ticles, but dissolves furfural very sparingly, whereas the furfural willeffectively act upon the solution as 'a wash to pick up the soft waxes. This washing step may be effected upon the filtered solution passing from filter 5, whereupon the furfural is separated from the'solutionxand the latter is steamed free from solvent. The

final product thus'obtained is-jsimilarit'ochicle in physical characteristics. It. will solidify into a block which is firm and nonrubbery'and nonfiexible at roomtemperatures and which will snap-break. The amount 'of fatty acids and waxes thus removed has amounted in certainoperations to about 4% of the final product.'.-": i

'In the practice of the 'duplexapparatus, as diagrammatically shown in Figure ,2, and withthe simplified apparatus of Figure 3, advantage may vbe taken of the discovery "by us that. the fibers of the ground plant particles'are operative directly to support and retain the adsorption material for adsorbing the chlorophyl and-further insuring the discharge of a clearsolution; This practice eliminates the necessity forgthedehydrator 3, the adsorber Land the filter. I

In practicing theprocess with'the duplex apfparatus'of Figure 2, extractors lZcc, 12mm, may

be charged with20 pounds of dry Asclepeiadaceae plants which will be ground, preferably to "10- mesh and intimately mixed. with adsorbent material, 4pounds offullersearth being an example. .The solvent ;reser,voir l Saxwill. be filled with 14 gallons ofsolventandthesolventmay be pumped by meanspf 'pumpil'la: througheonduit t5; and branch I523: to, thesprayt. discharge astral-"1 member within the top ofextractor 121:. With valve I611" closed andvalve I 1 opened (valve I8 being closed) the solvent may be circulated through extractor lZsc for five hours-with constant stirring and thesolvent level may pref-'- erably be kept at the central point of sight glass [Sat the topo-f the extractor.

-At the end of the five hours, extractor I29: may-be drained into tank I323, i. e.,-the solvent reservoir.- In practice, it has been found that about gallons of solution will thus drain of)? in about thirty minutes, about 3% gallons being held by the ground plant fibres. Thesolution; thus freed from chlorophyl, is of pale ambercolor. The next step is to remove the softer waxes. This soft wax is a yellowish-brown color and somewhat of the consistency of Vaseline at normal room temperatures, as contrasted with the desirable waxes which are firm at room temperatures and range upward in hardness to about that of carnaubawax.

Assuming that V. M. P. solvent has been employed in the extractor, the solution is pumped directly into a tank with an inverted cone base such as that shown at 40 in Figure-3, the tank containing furfural, pound of furfural to-each ti-pounds solution. The temperature of the furfural should be about 50 C. and when the solu tion meets the furfural a homogeneous mixture results, the latter being passed to a vessel :48 which is provided with a jacket for initially receiving steam at 50 C. and the homogeneous warm mixture then is passed to a decanter diagrammatically shown at50 and having a con- 'ical bottom, the vessel being surrounded by a cooling medium. The furfural with the dissolved-out soft wax is drawn from the base of vessel 50 and the V. M. -P. solution is decanted through conduit 5|.

The withdrawn solution is then passed to a still for removal of all but traces of the solvent and the substantially solvent-free material still containing the vegetable oil is passed to a steam still or vacuum pan by which thevegetable' oil is extracted, the process then being complete.

In the use of the duplex apparatus of Figure 2, employing a separate adsorber and benzol, for example, as the solvent, the ground plant p articles in extractors l2x, 12mm, will alternately be subjected to the action of the solvent. The solution passing from extractor [2x to collection tank I33: will then be pumped through conduit 23 and branch conduit 24 to dehydrator 25 which will contain a moisture absorbing medium'which as anhydrous sodium sulphate or carbonate and the contents of the dehydrator will be continuously stirred, for fifteen minutes. The moisturefree solution will then be led through a strainer 26 to tank 2'1. The next step is to blow the dry solution from tank 21 through conduits 28 and 29 to adsorber 30 wherein fullersearth or its equivalent will be intimately associated with the solution by stirring. The solution is then blown through conduit 3| into vacuum filter 32 which removes th adsorbent. Filtered material is passed through discharge conduit'33 into a collecting vessel 34 from which it may be passed viav conduit 35 to a still for removal of the solvent after which the solvent-freed product may be steam stilled for removal of the oil, the fatty acids neutralized by the addition of calcium oxide as hereinabove described.

In the operation of the duplex apparatus, while an extraction step is being performed in extractor l2m, extractor IZwa: may be steamed to remove the-solveht still held' bythe ground plant partfcles, and" the reverse ls -ti 'uewhen extractor I 2a: is performing its 'extraetion 'step. -'the case of each ext'ractor during steaming the. solvent 1 and -meisture vapors pass upwardly to valve controlled conduits 36-,-'-36:r,-to a condenser iil andfrom the condenser to a solvent andwvater separator. I

. At 38 anemergency tank is shown which has a valve controlled connection 39: with thefilter so that if'the filter becomes-deranged the solutionmay ibe diverted from tank 34' (which leads to the still) andpassedinto said emergency tank 38 -for further' treatment. I Thus the contents of emergency tank 3'8-'m'ay be blown through valve controlledbranch"conduit 39 into conduit 29 leading totheadsorber 30 from which it may again be blown to the filter after repair of the latter.

In the employment of" our simplified method with the apparatus 'di'agrammatically illustrated in Figure 3, the extractor 40 is charged with the ground plants, for-example; 20 pounds, intimately mixed with the-adsorption material, for example, 4 pounds, fullers earth; --14 gallons of V. M. P.-so'lvent naphtha will be placed in tank 4| and byfmeans of pump 46 the solvent will be cycled through the extractor, passing upwards through conduit" to the sprayhead 43' within the extractor. lnthis operation'valve 44 will be closed and valve 45 opened. This recycling may continue for five hours. --A-t--this point valve 45 is closed and'valve --44*opened"and the operation of the pump, indicated at,46, will be continued until the reservoir 4| isempty'and the subsequent draining of the extractor through conduit 41 will flow the solution into steam-jacketed mixer "charged with /4 pound furfural for each 5 pounds of the solution. The preferred temperature within the mixer is 50 0. While the solution is being transferred to the mixture, valve 49 will be closed. l

The mixing of the solution and furfural takes place rapidly and thereupon valve 49 is opened and the solution drained into separator 50, the j latter being provided .with .a cold. water jacket.

Valves 5| and 52 will re'main closed until-the liquid hasbeen cooled. and separationbfiectlad. Generally three hours issufiicient fortheseparation. Thereupon, the furfural and the softer waxes brought into solution therein-will settle at the conicalv base of the separator and. may. be drawn off by opening valve 52, after. which valve 52 .will be closed, valve 5| opened and the solution drawn oil to an initial still for stripping the solution of solvent, whereupon the substantially solvent-free product may be led to a steam still or vacuum pan for stripping off the remaining traces of solvent and freeing the product from the vegetable oil.

Inasmuch as-the proportion ofv softer waxes is not high, the furfural drawn from the separator 50 may be immediately re-used, its small wax content not impairing its efliciency. In fact, the furfural' maybe re-used several time before strippingit from the wax and employing it. in

pure :form for theseparating step.

It thus will beseen that in the operation of our process. a product 'may' be obtained free from chlorophyl and ofsuch substantial improvement over an initial extraction product obtained from the grown plants, as to enable the chlorphyl-free product to be directly used in large proportions for a blending agent with other crude gums, the blended product being suitable 7 Finally, an excellent gum product having physi+ cal characteristics. similar to those of chicle, may be obtained'by removal of the softer waxes or the fixing of the softer waxes, orv the neutralization of the fatty acids, the removal of thersoftcr waxes being preferable.- r

The phenomenum observed with respect to'the selective action of the. furfural upon the .waxes in that the furfural picks up the softer waxes and does not affect the harder waxes, may be due not only to greater aifinity between the furfural and the softer waxes, but to the fact that the gutta content of the solution. holds and protects the harder waxes.

The product freed of chlorophyl and vegetable oils, and with removal or fixing of the fatty acids, has the following general composition:

I. General composition in percent total gum:

a. Gutta 11% S. P 116 C. Type Caoutchouc,

I tough, elastic e (15 C.) b. Total resins 82% Av. S. P 65 C. c. Non-gutta-resin constituents:

Sugars None Fats andwaxes f. 7%

II/Composition of resins:

a. Crystalline albans "50% Hard, M. P.'range Mil-170 C. Chemical type. Terpene 1Soft, M. P. range"--- 131-133 C. b; Fluavils 32% M. P. rangem 4.0-43 C. f Chemical type. Unsaturated sterols S. P. denotes softening point. M. P. denotes melting point.

By the fixing of fatty acids they are converted, into a water in'soluble soap which is firmer than.

the waxes themselves and does not tend to emulsify in the gum. I v

It will be noted that the furfural is immiscible with the solution when cold but becomes miscible with it when warm. By war'm" is meant about 50C.orabove. W

With regard to the simplified apparatus and,

' Our new product maybe blended with excel lent results with all of the class of materials represented in the chewing'gum industry by'chicle gelutong, Gutta iHang Kang, Perillo Colombian and other perillos such as PerilloPanam'a; By

the equivalent of these materials is meant those fchicle substitutes which are generally used in the industry for preparation of chewing-gum bases,

-Having described our invention, what we claim and desire to secure by Letters Patent, is as follows: 7 V

1. A process for the recovery of gum constituents from Asclepiadaceae plants which comprises: eXtracting the solubles from the substantially dry comminuted plants by the solvent action of a member of the group consisting of aromatic hydrocarbon solvents and naphtha 'to form a solution thereof; and removing the chlorophyl from said solution extract by the adsorbtive action of infusorial earth.

2. A process for the recovery of gum constituents from Asclepiadaceae plants which comprises: extracting the solubles from the substantially dry comminuted plants by the solvent action of a'member of the group consisting of aromatic hydrocarbon solvents and naphtha to form a solution thereof; removing the chlorophyl from said solution by the adsorbtive action of infusorial earth; substantially stripping the solvent from the solution and removing the vegetable oil from the residue by steam distillation.

3. A process for the recovery of gum constituents from Asclepiadaceae plants which comprises: extracting the solubles from the substantially dry comminuted plants by. the solvent action of a member of the group consisting of aromatic hydrocarbon solvents and naphtha to oil from the residue by steam distillation; and'as V a step in the process, converting fatty acids carried by said extract into a water insoluble soap. 7

4. A process for the recovery of gum constituents from Asclepiadaceae plants which com-' prises: extracting the solubles. from the substantially dry comminuted plants by the solvent action of naphtha to form a solution thereof;

removing the chlorophyl from said solution by a the adsorbtive action of infusorial earth; removing soft waxes from said solution bylwashing said solution with furfural; and stripping the solvent r from the said dewaxed solution.

5. A process for the recovery of gum constituents fromAsclepiadaceae plants in accordance with claim 3, in which the solution, which contains chlorophyl, is subjected to the adsorbent material in successive batches of said adsorbent material, each insufiicient in itself to completely adsorb the chlorophyl content. I

6. A process forthe recovery of gumconstituents from Asclepiadaceae plants which comprises: extracting the solubles from the substantially dry comminuted plants by the solvent action of naphtha to form a solution thereof;- removing the chlorophyl from said solution by the adsorbtive action of infusorialearth; adding furfural to said solution at a temperature sufficient to effect miscibility of furfural and the said solution; reducing the temperature to cause stratification of the furfural thereby to remove softer furfural soluble waxes; removing the furfural layer; and recovering the solubles from the other layer.

'BORIS N. LOUGOVOY.

CARL E. HARTWIG. 

